Wireless relays have shown potential for extending communication range and providing good quality of experience. In a typical wireless communication system utilizing relays, the relay station would be time shared between different sources and destination. In such a scenario, the relay station needs to estimate the Angular Carrier Frequency Offset (ACFO) present between each pair of source and relay antennae (denoted ACFO Φr). The ACFO that is present between each pair of relay and destination antennae (denoted ACFO Φd) will be compensated for at the destination.
Joint compensation of the source to relay and relay to destination ACFO is not possible in the prior art. Compensation for the source to relay ACFO Φr can thus only be performed at the relay station. The relay station of the prior art will need to estimate and compensate the ACFO for each source-and-relay pair and this complicates the relay station hardware and increases the power required by the relay station.
Implementations of analog space-time coding (ASTC) in the prior art also have the limitation that the transmission channel has to be flat fading. This is because inter-symbol interference (ISI) results when the transmission channel has frequency selective fading. The insertion of a cyclic prefix (CP) can be used to mitigate against ISI. The cyclic prefix inserted should preferably be of a length greater than that of the channel impulse response (CIR).
Typical implementations of ASTC also require that the samples within a signal be re-ordered when performing the coding.
It is an object of the present invention to provide a method for implementing cyclic prefixes and compensating for the channel effects of a wireless communication channel, which addresses at least one of the problems of the prior art and/or to provide the public with a useful choice.